The European Union and the United States are considering targeted sanctions against Burmese military leaders over an offensive that has driven more than 500,000 Rohingya Muslims out of the country, officials familiar with the discussions say.

Following the resignations of three Arakan National Party (ANP) lawmakers in as many days, the trio intend to join the rival, resuscitated Arakan League for Democracy (ALD), according to the ALD’s general secretary.

Two defections this week by sitting lawmakers formerly pledging fealty to the Arakan National Party (ANP) have made clear that divisions within one of Burma’s most formidable ethnic political parties continue to fester.

A top Burmese official appealed on Monday for democracy in the country to be given “a chance to survive” amid international anger over a military campaign against Rohingya Muslims that the United Nations has described as ethnic cleansing.

Two senior Burmese government officials have delivered aid to a remote Rohingya Muslim village, and guaranteed residents’ safety, after they were cut off and threatened by hostile Arakanese Buddhist neighbours, one of the officials said.

US Ambassador to the United Nations Nikki Haley on Thursday called on countries to suspend providing weapons to Burma over violence against Rohingya Muslims until the military puts sufficient accountability measures in place.

International aid groups in Burma have urged the government to allow free access to Arakan State, where an army offensive has sent 480,000 people fleeing to Bangladesh but hundreds of thousands remain cut off from food, shelter and medical care.

Burma has sent a list of hundreds of names of suspected terrorists to the Bangladeshi government, and is seeking to have those individuals detained for their alleged involvement in deadly attacks last month by the Arakan Rohingya Salvation Army in Arakan State, according to a senior Burmese government official.

In a speech last week, Aung San Suu Kyi said all people in Arakan State “have access to education and healthcare services without discrimination.” For critics, however, that’s simply not true — a contention supported by a report that Suu Kyi’s own government has embraced.

United Nations Secretary-General Antonio Guterres will publicly brief the Security Council on Thursday on violence in Burma, which he has described as ethnic cleansing, after seven countries on the 15-member body requested the meeting.

Muslim refugees seeking shelter in Bangladesh from “unimaginable horrors” in Burma face enormous hardship and risk a dramatic deterioration in circumstances unless aid is stepped up, the head of the UN refugee agency said on Monday.

Burmese government forces found on Sunday the bodies of 28 Hindu villagers who authorities suspected were killed by Muslim insurgents last month, at the beginning of a spasm of violence that has sent 430,000 Muslim Rohingya fleeing to Bangladesh.

Relief agencies struggling to reach hundreds of thousands of Rohingya Muslims displaced by strife in northwestern Burma are facing rising hostility from ethnic Arakanese Buddhists who accuse the United Nations and foreign aid groups of only helping Muslims.

Burma’s army chief called on Thursday for people internally displaced by violence in Arakan State to go home and rebuild communities, but he made no mention of 422,000 Rohingya Muslims who fled to Bangladesh to escape his forces’ operations.

Hundreds of Buddhists in Burma tried to block a shipment of aid to Muslims in Arakan State, where the United Nations has accused the military of ethnic cleansing, with a witness saying protesters threw petrol bombs before police dispersed them by firing into the air.

UN investigators have started collecting testimony from fleeing Rohingya Muslims pointing to human rights violations by Burma’s military and security forces, the head of the fact-finding mission said on Tuesday.

Burma said on Friday a visiting US official would not be allowed to go to a region where violence has triggered an exodus of nearly 400,000 Rohingya Muslims that the United Nations has branded a “textbook example of ethnic cleansing.”

The US Senate majority leader Mitch McConnell said on Thursday he had spoken with Aung San Suu Kyi and that she said she was working to get aid to the Muslim areas in Arakan State that were affected by violence.